Interlock space saving containers



A. E. MILLER 3, 6 I NT ER LOCK SPACE SAVING CONTAINERS I Aug. 19, 1969 2 Sheets-Sheet 1 Filed se k. 20, 1967 INVENTOR.

ALVIN E. MILLER BY j M v ATTORNEY United States Patent 3,462,062 INTERLOCK SPACE SAVING CONTAINERS Alvin E. Miller, 4 Hampstead Road, Asheville, N.C. 28804 Filed Sept. 20, 1967, Ser. No. 669,128 Int. Cl. B65d 1/00, 7/42 US. Cl. 229-8 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to a container for packaging either liquid, fluid or solid goods of any description,

and more particularly to a hexagonal carton specifically suited for stacking in multiple rows and layers.

One of the problems facing the consumer package industry is the selection of a container for enclosing the largest amount of goods in the smallest wall surface area with a minimum consumption of space when a plurality of such containers are arranged together for shipping purposes. The most efficient package insofar as concerns volume per area of container wall surface is the sphere. Stated differently, the least amount of wall surface is required for enclosing a given volume if the container is shaped as a sphere rather than as a cube, as a cylinder, or in some other configuration. The sphere, however, is one of the most inefficient shapes of all for purposes of close packing, i.e. for arranging packages in plural rows and layers within a shipping crate. Moreover, spheres will not stack one upon another as on a store shelf. Neither are they particularly attractive when displayed and, therefore, they do not enhance the sale of goods contained therein.

While not as efficient in volume to surface area as the sphere, the cylinder is widely used in the packaging field because it obviously stacks better than the sphere and because it can be arranged decoratively for display purposes. There are disadvantages, however, to use of the cylinderical shape. It will not close pack horizontally in shipping boxes any more efficiently than the sphere for apparent reasons. Moreover, even though cylindrical cartons can be stacked vertically one upon the other, the end walls cannot be made to interlock effectively and care must be taken to avoid dislodging one carton from the other. For these reasons even the cylindrical carton leaves much to be desired.

Close nesting of one carton adjacent to another for shipping purposes can be obtained with either three wall (triangular cross-section), four wall (rectangular or square cross-section), or six wall (hexagonal cross-section) cartons. Interlocking carton end walls having an even number of sectors which undulate (i.e. some sectors sloping upwardly, an equal number sloping downwardly) with respect to each other are not possible with three wall containers, however, because the walls cannot be divided into the required number of pairs, as will be described subsequently. The ends of our wall cartons can be divided into pairs of undulating or adjoining involute/ evolute sectors, but the carton will not stand in a perfectly vertical position because only two pairs of involute/evolute sectors produce two high points and two alternating low points in the circumference of the end walls. Triangular walled cartons can be devised with ice interlocking ends which point like an arrow at the upper end wall and which rest like a tripod at the lower end Wall. These two features are very desirable. Unfortunately, however, the triangular carton has the least volume to Wall surfrace area ratio and for that reason is not widely used. Cartons having more than six sides or walls are equally objectionable in that the ends cannot be interlocked as proposed herein either because of uneven number of walls or because the cartons cannot be close packed for shipping or display purposes.

A primary object of the present invention is to provide a carton which does not have the disadvantages enumerated above.

Another object of this invention is to provide cartons that can be both close packed for shipping purposes and interlocked if stacking is desired.

A more specific object of the instant invention is to provide a carton having the most efficient volume per wall surface area ratio which can be interlocked with similar cartons if stacking is desired and which is stable when resting on a shelf or other flat surface.

Still another object of this invention is to provide a system for interlocking one carton to a similar carton in which the cartons tend to align themselves automatically when placed one on the other.

These objects are accomplished, in accordance with the present invention, by selecting a hexagonal carton with end walls, and by dividing each end wall into six sectors with alternate sectors involuting and with the remaining intermediate sectors evoluting to form undulating planar surfaces.

Other objects and advantages will be apparent upon study of the following detailed description taken in conjunction with the accompanying drawings, wherein FIGURE 1 is a perspective view of a single carton;

FIGURE 2 is a plan view showing a plurailty of cartons nested in a close packed relationship for shipping or display purposes;

FIGURE 3 is an isometric view of two cartons having interlocked ends and being stacked vertically; and

FIGURE 4 is a plan view of a plurality of cartons arranged in a decorator stack for display purposes.

Turning now to FIGURE 1, it will be seen that the carton generally designated by reference numeral 10 is formed from six side walls or panels 11 and two end walls 12, 13 (only the former of which appears in full view). While the preferred form of this carton is a regular hexagonal with six equal sides, non-regular or asymmetrical hexagonal shapes could be used with a sacrifice in volume to wall surface area efficiency and with less convenience in stacking and close packing. The carton, of course, may be formed from any metallic or non-metallic material, depending on the type of goods to be stored, and preferably is formed from a hard paperboard.

The end walls 12, 13, which normally would be flat, have been divided into six triangular sectors 14, 15, 16, 17, 18, and 19 which undulate about the center point 21. In other Words, the circumferential edge of sector 14 slopes upwardly toward corner or vertex 22, while the circumferential edge of sector 15 slopes downwardly away from the vertex 22. Likewise, the outer edge of sector 16 slopes upwardly toward vertex 23 while the outer edge of sector 17 slopes downwardly away from this vertex, and the circumferential edge of sector 18 slopes upwardly toward vertex 24 while the outer edge of sector 19 slopes downwardly therefrom. This undulating surface characteristic is described herein with reference to sectors 14, 16, and 18 as being involute and with reference to intermediate sectors 15, 17, and 19 as being evolute.

It will be apparent from inspection of FIGURE 1 that the three vertices or corners 22, 23, and 24 are raised slightly With respect to the remaining (unidentified) corners and with respect to the center 21 of the end wall 12. If the angle of slope of the various sectors with respect to the horizon (or with respect to a right plane passing through the hexagonal container) remains constant (but of course with the involute sectors having positive angles of slope and with the evolute sectors having negative angles of slope, as is preferred), the three vertices 22, 23, and 24 will support the carton in a perfectly stable and completely vertical position. If the angle of slope of the various sectors at the opposite end 13 of the carton is the same, then the end 12 of one carton will nest with the end 13 of a second carton, and so forth. Moreover, the end 12 of a first carton need not be rotated manually to nest with the end 13 of a second carton since the three raised edges extending between the center 21 and respective vertices 22, 23, and 24 will serve to align the two cartons and the weight of one carton stacked vertically on another, in most instances, will be sufiicient to cause sliding movement between mating sloped surfaces and relative rotation of the top carton on the bottom carton will occur until the two end surfaces are fully seated one on the other.

According to Mathematical Snapshots by H. Steinhaus, published by the Oxford University Press in 1960, p. 86, a plane can be divided into a given number of equal areas with the least amount of material if the areas are formed in the shape of a hexagon. In other words, an acre of pasture can be divided into forty (for example) individual grazing areas of equal size with the least amount of fencing if each area is formed in hexagonal shape. This principle of wall economy has been employed, as indicated earlier, in the design of the carton presently under consideration. See, for example, FIGURE 2 wherein the honeycombed illustration represents a plurality of cartons 10 close packed in horizontal rows. Since a regular hexagonal shape has been selected, the carton 10 may be randomly inserted Within shipping crate 25 and need not be rotated or manipulated in any way to produce close nesting. The only wasted space, so to speak, is along the inner circumference of crate 25 where voids inherently will occur. These voids, however, are substantially less than those created by spherical or cylinderical cartons and the interlocking feature permitted by a sixwalled carton more than offsets the complete close nesting advantage of a square or rectangular, or even triangular, carton. Moreover, as pointed out in Mathematical Snapshots, supra, less linear wall length (when viewed from the direction of FIGURE 2) will be required to fill the crate 25 with hexagonal cartons than with any other shape.

With attention directed to FIGURE 3 it will be seen that carton 10 may be stacked vertically without any loss of space through voids. While this phenonomenon of course is present when the end walls are formed in a single plane, the interlock feature is not. Through use of the undulating or involute/evolute end walls 12, 13 a vertical stack of cartons such as shown in FIGURE 3 can be tilted substantially from an exact vertical line without dislodging one carton from the other. This feature greatly facilitates handling and enables a stock clerk, for example, to load carts, stack shelves, pack crates or bags, and otherwise handle the cartons in a much faster and expeditious manner without the risk of droppage or damage. When the cartons are vertically stacked in store displays, there likewise is less risk of damage through collapse of the display when interlocked cartons are brushed accidentally by children or customers. An important aspect of this invention is the possibility of a carton interlock as explained without sacrifice either to the volumeto-wall surface efiiciency or to close nesting in either horizontal or vertical stacking.

If desired, either of the vertics 22, 23, or 24 could be used for a pouring spout through the appropriate addition of score lines to permit tearing by the consumer. This would appear to be highly advantageous when compared with conventional milk cartons, for example, which do not have provisions for carton interlock, which do not stack vertically, and which are not susceptible to vertical close packing. Since the cartons of this invention are supported throughout the end walls when vertically stacked, as shown in FIGURE 3, stacking of filled cartons should not create spillage because of carton rupture. Accordingly, the pouring facilities of conventional cartons is retained in carton 10 along with the added features discussed herein.

One carton 10 need not be stacked in axial alignment with a second carton 10, as illustrated in FIGURE 3, but may be offset in decorative display form as shown in the plan view of FIGURE 4. As a method only of illustration, and not by way of limitation, three cartons 10-1, 10-2, and 10-3 are close packed on a shelf or other surface (not shown). Each of these cartons is supported by three vertices similar to those indicated at 22, 23, and 24 in FIGURE 1. Inasmuch as three points not arranged in a straight line define a plane (elementary geometry), it will be seen that the vertices 22, 23, and 24 (or vertices similar thereto) form a tripod type base and the carton 10 Will always rest firmly on its support. Accordingly, each carton is supported at three points equally spaced about its axis and, therefore, is as stable as any known geometric figure. The vertex 24 of carton 10-1 is arranged along side vertex 24 of carton 10-3, while the vertex 22 of carton 10-1 is placed alongside vertex 22 of carbon 10-2. Likewise, vertices 23 of cartons 10-3 are aligned.

With the raised corners of adjacent cartons being placed alongside each other, and this is geometrically possible as will be seen from FIGURE 4, the involute/evolute sectors common to the three cartons exactly correspond to the end wall 12 of any single carton 10. Accordingly, a fourth carton 10-4 may be vertically stacked in the center of the other three cartons, as shown, and the same interlock exists as with the arrangement shown in FIGURE 3. A duplication of this feature occurs if more cartons are disposed in the lower and upper layers of FIGURE 4, and, of course, triple layers may be obtained by interlocking cartons onto the upper layer designated by carton 10-4. Moreover, some cartons in the upper layer may be aligned axially with cartons in the lower area and others may be asymmetrically aligned as shown in FIGURE 4, although there may be some space loses if both systems are used. Consequently, a variety of decorative displays may be obtained without loss of the interlock aspect and with very little, if any, loss in close packing.

As indicated earlier herein, the cartons may be formed of any suitable material such as tin, aluminum, copper, other metals, paper, fiberboard, plastic, etc. depending on requirements of the goods being packaged and the treatment to which the carton will be exposed. The shape described above may be obtained by fabricating and folding difierent sheets of material, by stamping or pressing, by molding, or in any other desired manner. The carton dimensions of course may be selected to suit demands of each particular end use.

The degree of slope from the horizontal of the sectors (the extent of involute and evolute) is not critical and could vary between about 3 and about 15 depending on the material used for constructing the carton and the weight of goods to be placed therein. In order to obtain the most efficient volume to wall surface ratio, the carton diameter should be about or of the carton height. Otherwise, however, there of course is no limitation on size. Moreover, the vertices at one end of the carton need not necessarily be aligned with those at the other end of the same carton and they may be staggered, although all cartons to be used common with one another of course should be similar as to size and construction. The important features are that the carton be hexagonal, that the end walls be divided into undulating sectors and that the sectors provide both interlocking function and a tripod type supporting base to insure stability whether the carton is placed singly on a shelf, is stacked vertically on and in axial alignment with 'another carton, or is stacked decorator style on two or more other cartons. All of these objectives are met, and in a very efiicient manner, with the carton described and claimed herein.

The present invention is believed to be a substantial improvement over US. Patent Nos. 2,919,800; 3,000,496; and 3,175,683 which described cartons having some but not all of the features discussed hereinabove.

What is claimed is:

1. A polygonal carton construction having end walls, each end wall being provided with a number of involute sectors and an equal number of evolute sectors to produce peripheral undulations and thereby provide a container which can be close nested horizontally with other similar containers without space voids, which can be vertically stacked with other similar containers without loss of space, which can be vertically interlocked with other similar containers without dislodging or space loss, which can be interlocked and decoratively stacked asymmetrically with other similar containers without loss of space, and which has a high volume-to-wall surface ratio to provide an economical container shape.

2. A polygonal carton as set forth in claim 1 wherein the number of involute and evolute sectors formed in one carton end is equal to the number formed in the other carton end.

3. A polygonal carton as set forth in claim 2 which is hexagonal.

4. A hexagonal carton as set forth in claim 3 which also has three involute sectors and three evolute sectors in each carton end.

References Cited UNITED STATES PATENTS 204,971 6/1878 Hill 220-66 2,030,862 2/1936 Fitch 296-35.1 XR 2,440,836 5/1948 Turngren 46--25 2,822,952 2/1958 Scott 220-97 3,010,888 11/1961 Battle 4625 3,070,257 12/ 1962 Bojanowski 22097 3,319,961 5/1967 Wilson.

3,369,727 2/ 1968 Wright 2298 XR FOREIGN PATENTS 1,421,520 11/1965 France.

DAVIS T. MOORHEAD, Primary Examiner US. Cl. X.R. 

